Initial Damage Disaster Report for Tropical Cyclone Harold: Tonga

In early April 2020, tropical cyclone Harold, a severe category 5 cyclone, hit countries within the Pacific region, causing major damage and widespread destruction. Following the cyclone, the National Emergency Management Office (NEMO) in Tonga, under the Ministry of Meteorology, Energy, Information, Disaster Management, Environment, Climate Change and Communications (MEIDECC), and together with supporting ministries and humanitarian agencies, acted quickly to lead and coordinate the Initial Damage Assessment (IDA) at the household level across Tongatapu and ‘Eua and other affected areas. The IDA was undertaken by conducting household interviews, damage verification and observation and remote sensing surveying using unmanned aerial vehicles (UAVs.) It was estimated that approximately 10 per cent of households in Tongatapu and ‘Eua were significantly impacted and needed urgent relief, with over 1,400 people being displaced. Patangata (Kolofo’ou District) experienced severe flooding during tropical cyclone Harold. The area of dryland that was used for living is now thinner and more exposed to flooding.

With assistance from the MORDI Tonga Trust, an International Fund for Agricultural Development, a UAV damage assessment survey was undertaken using small scale UAVs. These surveys, undertaken in high damage areas, showed major differences between the pre- and post-disaster scenarios in terms of severe land and building damage. Using space and geospatial applications, such as UAVs, post disaster assessments provide accurate, high resolution and quick imagery of the damage which would be difficult or expensive to gain elsewhere. Through the use of UAV surveying, areas of high concern can be quickly identified in order to alert authorities of where aid and support needs to be directed.

Additional details and more practices like this can be found in Geospatial Practices for Sustainable Development in Asia and the Pacific 2020: A Compendium